Herein, we conceptualized a transient mediator approach that has the capability of para-selective C-H functionalization of monosubstituted aromatics. This approach is enabled by in situ generation of a versatile sulfonium salt via highly electrophilic phenoxathiine or thianthrene dication intermediate which can be readily generated from its sulfoxide with tri-fluoromethanesulfonic anhydride. Preliminary mechanistic study implied that the remarkable para selectivity might be related to the incredible electrophilicity of thianthrene dication intermediate. The versatility of this approach was demonstrated via para-borylation of various monosubstituted simple aromatics combining the sulfonium salt formation with further photocatalyzed transformation.

中文翻译：

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使用瞬时介体对单取代苯进行对位选择性硼化

在本文中，我们概念化了一种瞬时介体方法，该方法具有单取代芳族化合物的对位选择性CH功能化的能力。这种方法是通过使原位生成一个多功能锍盐的通过高度亲电phenoxathiine或噻蒽双阳离子中间体，该中间体可从其与三fluoromethanesulfonic酐亚砜很容易地生成。初步的机理研究表明，对位选择性的显着性可能与噻吩类四氢呋喃中间体的不可思议的亲电子性有关。该方法的多功能性已通过para展示-mono化各种单取代的简单芳族化合物，并结合salt盐的形成和进一步的光催化转化。